[Dave Cridland] try to encode username, realm and password in iso-8859-1 when doing DIGEST-MD5 before computing the hash. Fixes #5512

msgfmt -c de.po complains about two errors though. They result from the fuzzy
clock. The complained arguments refer to the next hour and are resolved by
Gajim.

This is a workaround until the whole update_contact method is gone. It should not be needed.

(I don't think what we have here is good, but it is atleast readable)

One of the methods was duplicated. Additionally, apply a very few coding standards.

Remove logging of callback method calls. Such cross-cutting concerns are better directly implemented in the xmpp dispatcher.

Import socket in jingle_rtp, fixes typo in 'stun_server', connect changed signal of stun_server_entry Fixes #5502

Plan is to move our ConnectionX classess to the protocol package one by one. Each move should be more than a simple copy paste. It should be preceeded by cleanups and the like.

 * Make it testable and write a very basic test for the presenceCallback
 * Use Extract Method to make the code more readable and to increase reusability
 * Start to decouple ConnectionCaps from the other Connection classes/handlers